I don't know the official advice but I just experiment and usually find I want 1000-1400deltaV for boost back and landing. That's with Mechjeb, landing back at KSC.
I don't know if the figures work out but I usually boost to an apoapsis of 110km, seperate, boost back...change to second stage and circularise...then back to booster to land.
Hope that's useful in some way!